1. Field of the Invention
The present invention relates generally to a touch module, and more particularly to a touch module in which the wiring structure is changed.
2. Description of the Related Art
Along with the rapid development of information techniques and communication networks, various personal electronic information products have been more and more popularly used. To go with the tide, various touch panels have bee rapidly developed and applied to the electronic products. According to the sensing principle, the current touch panels can be mainly classified into resistive touch panels, capacitive touch panels, electromagnetic touch panels and optical touch panels. The capacitive touch panel structures have the advantages of dustproof, fireproof and high-resolution performances and are thus widely used. The working principle of the capacitive touch panel is that the touch point position is identified according to the change of capacitance. When a conductive touch article (such as a finger) gets close to the touch panel, the capacitance between the electrodes changes to identify the coordinates of the touch point.
The capacitive touch panels have gradually become the mainstream of touch techniques and are widely applied to various electronic information products nowadays, such as cellular phones, tablets, walkmans, handheld electronic devices, displays and monitors. The capacitive touch panel can detect the capacitance change caused by the weak current of human body to identify the positions of the finger and touch selection conditions so as to achieve the object of touch control.
Please refer to FIG. 1, which is a sectional view of a conventional capacitive touch panel. The conventional capacitive touch panel includes a first transparent substrate 10 and a second transparent substrate 11. One side of the first transparent substrate 10 has a touch sensing circuit layer 12 and a lead layer 13 in electrical connection with the touch sensing circuit layer 12. The touch sensing circuit layer 12 is a single-layer touch sensing circuit. The other side of the lead layer 13 has an insulation layer 14 partially covering the lead layer 13. A conductive glue layer 15 is disposed on an exposed section of the lead layer 13. A soft printed circuit board 16 is disposed on the other side of the conductive glue layer 15. The soft printed circuit board 16 is electrically connected to the lead layer 13 through the conductive glue layer 15. An optical glue layer 17 is disposed on the other side of the touch sensing circuit layer 12 distal from the first transparent substrate 10 and the other side of the insulation layer 14 distal from the first transparent substrate 10. The second transparent substrate 12 is attached to the optical glue layer 17. The other side of the second transparent substrate 12 distal from the optical glue layer 17 serves as the touch face of the capacitive touch panel. Also, the second transparent substrate 12 serves to protect the touch sensing circuit layer 12, the lead layer 13 and the conductive glue layer 15.
The projective capacitive touch panel is generally divided into a display section and a peripheral section around the display section. The touch sensing circuit layer 12 is mainly positioned in the display section for generating a touch sensing signal. The lead layer 13 and the conductive glue layer 15 are positioned in the peripheral section for transmitting the touch sensing signal to a signal processor for calculating the coordinates of the touch position.
The lead layer 13 is wired in the peripheral section to connect with the touch sensing circuit layer in the display section. When wired, it is necessary to bridge the lead layer 13 to respectively connect with the corresponding touch sensing circuit layer 12. Therefore, it is necessary to use optical mask and perform lithography and etching processes to the lead layer 13 for bridging the lead layer 13 corresponding to the touch sensing circuit layer 12. The cost for the optical mask and the lithographic and etching equipment is quite high so that the total manufacturing cost is inevitably increased. Moreover, the developer and etching liquid used in the lithography and etching processes are both chemical solutions harmful to human health. Therefore, the developer and etching liquid not only seriously threaten the health of the workers in the working site, but also lead to serious pollution of the ecological environment. In addition, it is necessary to use the optical glue layer 17 to adhere the first and second transparent substrates 10, 11 to each other. In the adhesion process, the first and second transparent substrates 10, 11 are likely to displace or fail to fully attach to each other. This will cause defective products. According to the above, the conventional touch panel has the following shortcomings:    1. The manufacturing cost is high.    2. The ratio of defective products is high.